{*../../docs_src/python_types/tutorial006.py hl[1] *}

Déclarez la variable, en utilisant la syntaxe des deux-points (`:`).

Et comme type, mettez `List`.

Les listes étant un type contenant des types internes, mettez ces derniers entre crochets (`[`, `]`) :

{*../../docs_src/python_types/tutorial006.py hl[4] *}

/// tip | "Astuce"

///

### Import `Depends`

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[3] *}

### Declare the dependency, in the "dependant"

The same way you use `Body`, `Query`, etc. with your *path operation function* parameters, use `Depends` with a new parameter:

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[13,18] *}

{* ../../docs_src/custom_request_and_route/tutorial002.py hl[13,15] *}

If an exception occurs, the`Request` instance will still be in scope, so we can read and make use of the request body when handling the error:

{* ../../docs_src/custom_request_and_route/tutorial002.py hl[16:18] *}

## Custom `APIRoute` class in a router

Let's say you have a Pydantic model with default values, like this one:

{* ../../docs_src/separate_openapi_schemas/tutorial001_py310.py ln[1:7] hl[7] *}

### Model for Input

If you use this model as an input like here:

{* ../../docs_src/separate_openapi_schemas/tutorial001_py310.py ln[1:15] hl[14] *}

...then the `description` field will **not be required**. Because it has a default value of `None`.

### Input Model in Docs

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[9] *}

In this case, **FastAPI** won't ever touch or care about `__init__`, we will use it directly in our code.

## Create an instance

We could create an instance of this class with:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[18] *}

The first step is to disable the automatic docs, as by default, those use the default CDN.

To disable them, set their URLs to `None` when creating your `FastAPI` app:

{* ../../docs_src/custom_docs_ui/tutorial001.py hl[8] *}

### Include the custom docs

Now you can create the *path operations* for the custom docs.

You can reuse FastAPI's internal functions to create the HTML pages for the docs, and pass them the needed arguments:

{* ../../docs_src/advanced_middleware/tutorial001.py hl[2,6] *}

## `TrustedHostMiddleware`

Enforces that all incoming requests have a correctly set `Host` header, in order to guard against HTTP Host Header attacks.

{* ../../docs_src/advanced_middleware/tutorial002.py hl[2,6:8] *}

The following arguments are supported:

{* ../../docs_src/python_types/tutorial003.py hl[1] *}

Because the editor knows the types of the variables, you don't only get completion, you also get error checks:

<img src="/img/python-types/image04.png">

Now you know that you have to fix it, convert `age` to a string with `str(age)`:

{* ../../docs_src/python_types/tutorial004.py hl[2] *}

## Declaring types

{* ../../docs_src/response_status_code/tutorial001.py hl[6] *}

`201` ist der Statuscode für „Created“ („Erzeugt“).

Aber Sie müssen sich nicht daran erinnern, welcher dieser Codes was bedeutet.

Sie können die Hilfsvariablen von `fastapi.status` verwenden.

{* ../../docs_src/response_status_code/tutorial002.py hl[1,6] *}

But FastAPI also supports using <a href="https://docs.python.org/3/library/dataclasses.html" class="external-link" target="_blank">`dataclasses`</a> the same way:

{* ../../docs_src/dataclasses/tutorial001.py hl[1,7:12,19:20] *}